Shenzhen Cansirong Trading Co., Ltd RX-021
Shenzhen Cansirong Trading Co., Ltd RX-021 is in the DOE listing as of Oct 19, 2026.
- Electric tankless water heater
- 1 listed model
ENERGY STAR certification does not cover this type of water heater.
Its figures are also listed under Rheem ECO POU 3.5.
Certified figures
- Flow at a 67°F rise
- 0.3gallons per minute
- UEF
- 0.95Uniform energy factor
Your fixtures at once
Change your hour and flowFlow where you live
Colder incoming water needs a bigger rise, so the heater gives less flow.
- Cold water
- Cold water must be at least 10°F colder than the hot water setting.
- Flow estimate
- The estimate uses the lowest certified flow among the listed models. It is about 0.3 gal/min at a 70°F rise.
Flow limits
- The estimate excludes the flow needed to turn the heater on, heat lost in pipes, and installation.
- Cold water from a well or long pipe run can differ from the temperature you enter.
- Without a stated flow limit, estimates for warmer water may exceed the heater’s actual flow.
Certified figures by listed model
| Model number | UEF | Flow at a 67°F rise (gal/min) | Recovery efficiency | Draw pattern |
|---|---|---|---|---|
| RX-021 | 0.95 | 0.3 | 98% | Very small |
UEF is the uniform energy factor. A dash means the model has no such figure.
It warms 0.3 gallons per minute of water from 58°F to 125°F in the test. The median flow among electric tankless models is 0.7 gallons per minute. Among 337 electric tankless models, 271 give more flow at a 67°F rise.
In tests, 95% of the energy it uses ends up as hot water (UEF 0.95). Its test simulated a day of very small hot water use (its draw pattern). Of 272 electric tankless models with the same draw pattern, 151 have a higher UEF. On its draw pattern, the median electric tankless UEF is 0.96. Of the energy it spends heating water, 98% ends up in it (its recovery efficiency).
All of its test figures are shared by 3 other basic models. The ECOSMART, EEMAX, and Rheem brands list one or more of them. For the full group, see the Rheem ECO POU 3.5.
Also listed as
They carry every figure in the table above.
- Every Shenzhen Cansirong Trading Co., Ltd basic model
- Every electric tankless water heater certified below 1.0 gallon per minute
- Every electric tankless water heater
Not covered
- Advertised figures. We have none on file for this model.